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Identity our alternator (again)


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I have known, there is a past thread the mentions its, and probably even have a personal paper record of what model our alternator is but sat at my desk at work on this sunny good friday im dammed if I can find any of this.

 

And this is the best photo I can find online, its paired with a large (say 2*3inch) externally mounted durite regulator in a diacast aluminium case which is just about out of shot and used to work find until I removed it for access and work on in mounts and returned it (as far as I know) to exactly where and how it was before. To my knowledge its a standard unit, bar the fact its been rewired from delta to star topology.

 

emilyanne059rp6.jpg

 

I would also me interested in the effect of connecting the field terminals the wrong way round as this is the only mistake that could have in my mind been made as although the wires are well labelled and clear as to there being, and the alternator has a large ' + ' and ' - ' on the output terminals, however the field terminals where totally unlabelled so I ended up going off a drawing in our maintaince book from about 8 years ago which detailed the +ve feed going to the terminal on the same side as the - ve output and the controlled 'field' cable from the regulator going to the terminal on the side next to the +ve output?

Would swapping them and trying them the other way fry anything, assuming they aren't already wrong and fried. Otherwise I guess its a case of lifting it back off and taking it and the reg to a auto elec house which is what we ended up doing the first time it went in! Anything i can test with the boats multimeter (20yo fluke with no power-current settings)

 

 

Daniel

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Looks like a Butec alternator which can use a Butec or CAV regulator with Hi Med & Low terminals on it.

 

 

http://woodauto.com/zoomImg.aspx?Ref=VRG3694

 

http://woodauto.com/controls/comp/showImage.aspx?waRef=VRG3695B&s=250

 

If you can identify which one it will help as would a photo of the terminals on the back of the alternator.

 

Cheers

 

Chris

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Looks like a Butec alternator which can use a Butec or CAV regulator with Hi Med & Low terminals on it.

 

 

http://woodauto.com/zoomImg.aspx?Ref=VRG3694

 

http://woodauto.com/controls/comp/showImage.aspx?waRef=VRG3695B&s=250

 

If you can identify which one it will help as would a photo of the terminals on the back of the alternator.

 

Cheers

 

Chris

 

I don't see why reversing the field connections would do any harm, I know it doesn't for the somewhat similar CAV AC5 alternator.

 

Is yours 24V? If so, I happen to have a new CAV 440 reg in the back of my car, and will be down at The Port some time tomorrow afternoon, if that would be any help. Might even have a 12Volt one lurking somewhere, would have to look.

 

Tim

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I would also me interested in the effect of connecting the field terminals the wrong way round as this is the only mistake that could have in my mind been made as although the wires are well labelled and clear as to there being, and the alternator has a large ' + ' and ' - ' on the output terminals, however the field terminals where totally unlabelled so I ended up going off a drawing in our maintaince book from about 8 years ago which detailed the +ve feed going to the terminal on the same side as the - ve output and the controlled 'field' cable from the regulator going to the terminal on the side next to the +ve output?

Would swapping them and trying them the other way fry anything, assuming they aren't already wrong and fried. Otherwise I guess its a case of lifting it back off and taking it and the reg to a auto elec house which is what we ended up doing the first time it went in! Anything i can test with the boats multimeter (20yo fluke with no power-current settings)

 

 

Daniel

The alternator it an old Butec, they were built like a brick outhouse and had a good low speed ouput.

 

There is no technical reason why reversing the field connections would do the alternator any damage but sometimes there was a tri-diode that would at least prevent it working the other way round.

 

It's a long time since I worked on one of these but maybe if I saw it I would recall the detials. There is something in my distant memory telling me that the field might need flashed to get it working again.

 

What are the symptoms?

 

Regards

 

Arnot

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So what happenend?

I fixed it!

 

Not a classic wiring job but then on a steamer there isn't the same level of vibration to worry about.

 

It turned out that there was a tri-diode and this makes the field polarity conscious when used with the Butec regulator. Swapping the wires solved the first part of the problem. Then it didn't start immediately and I suspect that this was due to the reversed residual magnetism of the rotor due to the swapped wires but just might be a portent of problems to come such as brushes. However the Ellesmere gathering wasn't the time or place to start stripping it down.

 

The next part was the drive belts (there are now two of them). Those segmented belts really are not suitable for any decent sized alternator but tightening them up managed to get about 30A out of the system at moderate propellor speed so hopefully that batteries got some charge on the trip home.

 

Regards

 

Arnot

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Hi Arnot

 

Been a long time, One question As you look at the photo, which way is the rotation clockwise or anti clock.The belt in the photo is fitted for the rotation to be anti clock, which is wrong,because it will be trying to push the belt through the load instead of pulling through the load. If it is on the other hand rotating clockwise then the belt is on backwards. The taper in the links points to the rotation direction. With link belts it is critical to get the direction correct moreso than a vee belt. (not trying to teach grandad to suck eggs) :lol:

 

Big Col

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Hi Col,

 

Good point about the belts but there are now two belts and they are the later orangey plasticy type. I didn't notice but hopefully Dan will check the rotation out.

 

Thanks for the info by the way, I didn't realise that these belts were directional but now you mention it, it does make perfect sense.

 

My preferred method with these is to cut the buggers off with a sharp knife and consign them to the nearest bin.

 

Regards

 

Arnot

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As a rule I would concur. If memory serves me right, a few years ago DHutch was complaining about the time needed to change a normal vee belt as it required a shaft strip down to pass the normal vee belt over an open end. These belts save this strip down time by being able to split the belt, fit the belt around the fixed continuous shaft and then reconnect the belt, this was the solution for him at that time. I agree they are not the Ideal drive belt but fitted correctly they are not too bad. As I have already stated with most of these non factory add ons the problem usually lies with the belt trying to push the load round as apposed to pulling the load round.

 

Big Col

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As I have already stated with most of these non factory add ons the problem usually lies with the belt trying to push the load round as apposed to pulling the load round.

I'm not sure I understand this fully. Looking at the pic, the alt appears to be more-or-less equidistant from the engine pulley, so that both lengths of belt (above and below) are about the same. Surely if one side is "pushing" then the other side is "pulling", so how would you determine that it's wrong?

 

Tony

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As a rule I would concur. If memory serves me right, a few years ago DHutch was complaining about the time needed to change a normal vee belt as it required a shaft strip down to pass the normal vee belt over an open end. These belts save this strip down time by being able to split the belt, fit the belt around the fixed continuous shaft and then reconnect the belt, this was the solution for him at that time. I agree they are not the Ideal drive belt but fitted correctly they are not too bad. As I have already stated with most of these non factory add ons the problem usually lies with the belt trying to push the load round as apposed to pulling the load round.

 

Big Col

 

Tip: with awkward to replace V belts, tie wrap a spare out of the way but already over the drive pulley.

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Hi Arnot

 

Been a long time, One question As you look at the photo, which way is the rotation clockwise or anti clock.The belt in the photo is fitted for the rotation to be anti clock, which is wrong,because it will be trying to push the belt through the load instead of pulling through the load. If it is on the other hand rotating clockwise then the belt is on backwards. The taper in the links points to the rotation direction. With link belts it is critical to get the direction correct moreso than a vee belt. (not trying to teach grandad to suck eggs) :lol:

 

Big Col

 

???

 

So you're saying if the rotation is clockwise, the belt is on the wrong way. But if the rotation is anti-clockwise, the belt is still on the wrong way?

 

There are two ways it can go on. How can they both be wrong?

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???

 

So you're saying if the rotation is clockwise, the belt is on the wrong way. But if the rotation is anti-clockwise, the belt is still on the wrong way?

 

There are two ways it can go on. How can they both be wrong?

 

 

:P

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I'm not sure I understand this fully. Looking at the pic, the alt appears to be more-or-less equidistant from the engine pulley, so that both lengths of belt (above and below) are about the same. Surely if one side is "pushing" then the other side is "pulling", so how would you determine that it's wrong?

 

Tony

 

I'm still trying to work out how a belt works other than by pulling. You sure as hell can't 'push' anything with a flexible belt

 

Richard

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I'm not sure I understand this fully. Looking at the pic, the alt appears to be more-or-less equidistant from the engine pulley, so that both lengths of belt (above and below) are about the same. Surely if one side is "pushing" then the other side is "pulling", so how would you determine that it's wrong?

 

And I'm still trying to work out how two pulleys, connected by a belt, can have one side of the belt longer than the other.

 

I'll give you a hint. It can't :)

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And I'm still trying to work out how two pulleys, connected by a belt, can have one side of the belt longer than the other.

 

I'll give you a hint. It can't :)

 

Well, when it's working, the working side will be in tension and therefore stretched, and the 'stretched' material will end up on the slack side, so I suppose technically there's more belt on one side than the other. But I don't think that's what you mean, so I agree with you

 

Richard

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Modern link belting is much better than the old fabric stuff, which seemed to stretch continuously throughout its life. It still has a much lower power rating then solid Vee or wedge belts, though (less than half, IIRC). It can do a perfectly adequate job if used within its ratings.

I don't know about a 'right way round' to transmit maximum power, but I always fit it the way round which will do least damage if someone or something rubs against it. Think of the top surface as a ratchet, you'll see what I mean.

 

Tim

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And I'm still trying to work out how two pulleys, connected by a belt, can have one side of the belt longer than the other.

 

I'll give you a hint. It can't :)

D'oh!

 

... the 'stretched' material will end up on the slack side...

I guess that's the side that's pushing ;)

 

Tony

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Where did he come from bloody smart a---e with his :P I thought you had joined the gentry Gibbo :P Well it would seem that I have had a senior moment here, :cloud9: I will explain many many years ago I was taught a system that should be applied to most belt driven appliances. Imagine a straight conveyor belt loaded with a product, that conveyor belt has to be pulled to work efficiently not pushed so the required direction of the conveyor will determine at what end the drive should be for it to pull the belt and the load. Then apply the same principle to any driven machinery drawing through the load leaving the slack on the return side.

Link belts are directional and there will be a positive side and a slack side when the alternator goes on load. With such a small pulley on the alternator the introduction of a third pulley for tensioning would probably help I can see this in my minds eye just not explaining it very well

 

Big Col

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I fixed it!

 

Not a classic wiring job but then on a steamer there isn't the same level of vibration to worry about.

 

It turned out that there was a tri-diode and this makes the field polarity conscious when used with the Butec regulator. Swapping the wires solved the first part of the problem. Then it didn't start immediately and I suspect that this was due to the reversed residual magnetism of the rotor due to the swapped wires but just might be a portent of problems to come such as brushes. However the Ellesmere gathering wasn't the time or place to start stripping it down.

 

The next part was the drive belts (there are now two of them). Those segmented belts really are not suitable for any decent sized alternator but tightening them up managed to get about 30A out of the system at moderate propellor speed so hopefully that batteries got some charge on the trip home.

 

Regards

 

Arnot

Nice one! I know these alternators like the back of my hand, lovely robust machines, with as you say good low speed output and with this one reconfigured in star in to the bargain the low speed output puts a very high torque loading on the drive. I remember Dan had big issues with belt slip as a result and doubling up was the solution. The linked belts were in my view a sensible solution to the problem, chain would be the rolls royce solution but I believe they have been reliable and low maintenance enough? Due to the star reconfiguration you won't get more than about 40A however hard you rev it from what started as a 60A machine so that 30A sounds respectable to me. Wouldn't worry too much about brush wear, I've never known one of these fail due to brush wear and have seen some very high mileage examples

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